Increasing the ability of plants to take up essential minerals could have a dramatic impact on both plant and human health.  For example, iron deficiency affects over 3 billion people worldwide and plants are the principal source of iron in most diets.  We have employed the tools available in the model plant Arabidopsis to identify genes involved in metal homeostasis.

We have discovered that iron reductase FRO2 and iron transporter IRT1 are expressed in iron deficient plant roots and are responsible for uptake of iron from the soil.  IRT1 is one of the founding members of the ZIP family of metal transporters, with representatives in bacteria, fungi and animals. 

Our lab is also currently trying to unravel how both plant and bacterial cells perceive iron status and translate that information into changes in gene expression.  We have recently identified a transcription factor, FIT1, that controls the iron deficiency response in Arabidopsis.

In addition, the bacterial side of our lab is trying to decipher the early signals that help set up the nitrogen-fixing symbiosis between bacteria of the genus Bradyrhizobium and its host, soybeans.  We are particularly interested in the period after the bacteria have entered the host via infection threads.  We are characterizing an interesting mutant that is unable to set up a persistent infection.  This mutant no longer expresses an iron-regulated operon that functions in free-living bacteria to take up iron.